Traditionally, pizza shells heve been formed by pressing, kneading and stretching a ball of proofed dough by hand into a relatively thin shell with a relatively thick rim. Generally, efforts to automate this process of kneading dough for pizza shells have not been successful in that mechanisms involved have not been able to simulate the manipulations of the human fingers. Some automated devices simply flatten and squeeze the dough between a pair of rollers, which are in the nature of a washing machine wringer. Any gas pockets in the dough tend to be flattened and ruptured and the pizza shell is not light and fluffy but, instead, flat and unappetizing. A hand operated roller configured to simulate hand kneading and shaping of a pizza shell has been disclosed in U.S. Pat. No. 4,815,859 for "Roller For Making Pizza Shell". The roller illustrated and described therein has a plurality of rounded knobs, which are spaced in annular rows, and the roller has to be rolled back and forth over the dough in order to cover the complete surface thereof. Moreover, the roller is designed to knead manually a single pizza shell, and is not adapted for mass production.